Tool for driving in and guiding pegs for fixing stakes

ABSTRACT

A tool for driving into the ground pegs having a central sleeve and projecting fins, said pegs being adapted for anchoring stakes into the ground, said tool comprising a rod-like body with pointed lower end and a projecting central part forming a lower transverse surface which is adapted for bearing on the projecting fins of the peg and a ram member sliding along the upper part of the rod-like body to impart blows on said projecting central part. The tool of this invention has a bell-shaped member capping the projecting central part and a flat member assembled to the base of the projecting central portion. It has particularly high resistance to the blows and allows easy replacement of its most fragile parts in case of wear or breakage.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the anchorage, in the ground, of posts orstakes by means of a peg having a rigid part, advantageously formed ofmetal plates shaped as fins, said rigid part forming a sleeve forreceiving the base of the post or stake once the peg has been driveninto the ground.

2. Description of the Prior Art

For driving such pegs into the ground there has priorly been proposedusing a tool comprising a rigid elongate body and a sleeve forming aram, mounted for sliding on the upper part of said elongate body so asto cooperate with a flat upper transverse surface of a central washerwith which said elongate body is fitted, whereas a lower transversesurface of said washer, situated at a distance from the lower end ofsaid elongate body slightly greater than the height of the peg, bears byits peripheral portion on the rigid part and is provided with a centralrecess. With such a tool, the operation for driving in a peg is achievedby introducing, into the sleeve thereof when it is simply laid on theground in a vertical position, the lower part of the body of the tool,which thus plays the role of a false stake, over a length slightlygreater than the height of the peg, so that the lower end of the body ofthe tool penetrates slightly into the ground. Then the ram, provided forthis purpose with operating handles, is caused to slide over the upperpart of the body of the tool so as to impart repeated blows on saidupper transverse surface or striking surface. The lower transversesurface or bearing surface transmits the impacts to the upper edge ofthe fins of the peg and drive this latter into the ground along thegeneral axis of the tool with guiding by the upper part of the body ofthe tool. When the peg has been driven completely into the ground, thefalse stake is withdrawn and a stake is introduced into the sleeve ofthe peg until its base penetrates slightly into the ground, to the depthreached by the lower end of the false stake. during the operation fordriving in the peg, the central recess of the bearing surface of thetool protects the sleeve of the peg from damage through upsetting whichwould prevent the subsequent positioning of the stake.

Finally, this tool allows the peg to be well driven into the groundwithout deforming it and without letting the earth penetrate into itssleeve.

It presents however a difficulty in construction due to the fact thatthe application of violent shocks causes considerable risk of breakage,in particular at the level of the central protuberance of the body or ofthe junctions of the handles with the ram.

The invention provides a tool of the above-defined type which offers aparticularly high impact resistance and further allows easy replacementof the most fragile elements in the case of wear or breakage.

SUMMARY OF THE INVENTION

According to the main feature of the invention, the central part of theelongate body comprises: an upper portion with larger section capped bya bell-shaped part whose upper surface is provided with a centralpassage for the upper part of the elongate body and forms said strikingsurface; and a lower portion whose section has a dimension equal to thecircle inscribed in the horizontal section of the sleeve of the peg,said lower portion being surrounded by a flat part whose lower surfaceforms said bearing surface and whose upper surface is connected to thebase of said bell.

According to another feature of the invention, the lower part or pin ofsaid elongate body comprises a lower end portion whose section has adimension substantially equal to that of the sleeve of the peg andhaving a pointed end and an upper portion connected to said lowerportion of said central part and of reduced section.

According to a preferred embodiment, the whole of said elongate body,including its upper part or handle, its central part with its twodifferent sections corresponding to two separate cylindrical portions orto a single truncated cone shaped portion and its lower part with aportion of reduced section and a pointed endmost portion or "plug", isformed in a single piece, advantageously by casting or forging whereasthe striking bell and the flat bearing piece are added parts.

According to an additional important feature of the invention, thehandles of the ram have a lower end made integral with the body of thesleeve, preferably by a long longitudinal weld, whereas their curvedupper end penetrates freely into a longitudinal channel which opens atthe upper end surface of the sleeve and has a depth greater than thelength of the handle portion which penetrates therein.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features as well as the advantages of the invention will clearlyappear from the following description.

In the accompanying drawings:

FIG. 1 is a longitudinal sectional view of the elongate body of a toolaccording to a preferred embodiment of the invention, of which

FIG. 2 shows the ram, also in longitudinal section;

FIG. 3 shows said ram in cross section; and

FIGS. 4 and 5 show, in perspective, two embodiments of the striking belland of the bearing part.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 it can be seen that the elongate body of the tool, formed, inthe preferred embodiment described, as a single cast piece, whichprocess allows a body to be obtained inexpensively in which thelongitudinal fibers of the metal (steel for example) are preserved andthus offer great tear strength comprises: a cylindrical handle 1, forexample 30 mm in diameter and 900 mm in length, a central part 2, formedof an upper cylindrical portion 20 with a diameter for example of 50 mmand a lower cylindrical portion 21 for example 50 mm in height and 35 mmin diameter which corresponds substantially to the dimension of theinscribed circle of the section of the sleeve (112, FIG. 1) of the peg(11) the most generally used; and a pin 3 formed of a lower pointed plug32 with a height of 190 mm and a section the same as that of the sleeveof the peg and an upper portion 31, 260 mm in height and with a reduceddiameter equal to 28 mm in the example considered.

The upper portion 20 of the central part is capped by a bell 4 having,for example, an outer diameter of 80 mm and a height of 65 mm andfitting exactly over said upper portion 20, a central passage 41 forhandle 1 to pass through its upper striking surface 42. The bell restsat its base on the upper surface of a flat part 5, 30 mm thick andhaving a central circular preservation recess 51 of a diameter forexample of 60 mm, and through which the portion 21 passes coaxially.

The lower surface 52 of the flat part 5 serves as bearing surface andits largest dimension is for example equal to 250 mm. The said bearingsurface is applied on the upper edge surface of the wings 110-111 of thepeg 11, as illustrated in FIG. 1.

Advantageously, this bearing surface is not circular but comprises forexample one of the shapes lightened by recesses 57;58 illustrated inFIGS. 4 and 5, where it can also be seen that the bearing piece 5 isprovided with strengthening fins, such as 53 to 56, integral with thestriking bell 4, whereas the bearing surface is provided with one ormore longitudinal notches, such as 59, which facilitate positioning onthe fins of the peg. Of course, the shape of the bearing surface will beadapted to the geometrical configuration of the fin assembly.

It will be noted that the central part in the shape of a protuberance 2has a high mechanical strength and allows, on the one hand, a spigotelement 20 to be formed for the striking bell 4, and on the other hand aportion 21 which cooperates with plug 32 for providing relative guidingof the peg and of the false stake.

With the striking bell, the section of the striking surface with whichthe base of the ram cooperates can be increased without for all thatexcessively increasing the section of the body of the tool, which mustbe as light as possible.

Plug 32 has over the whole of its height, except for the pointedportion, a section such that its shape matches perfectly that of thesleeve of the peg, within a few tenths of a mm and lubrication isrecommended for facilitating withdrawal of the tool at the end of thedriving operation. The very small thickness of the clearance preventspenetration of earth therein during driving in.

The intermediate reduced section 31 reduces the risk of adhesion of thefalse stake to the sleeve.

The bearing piece 5, bell 4 and even the central guide portion 21 andplug 32 may be removably mounted (by screwing, or by a spigot joint) soas to be able to be changed in the case of wear or breakage, or else, inso far as the plug and the central guide portion are concerned, forusing the same tool for pegs having sleeves of different sections. As avariant, it is possible to give the central part 2 the shape of atruncated cone whose upper base will have a diameter of 50 mm forexample and whose lower base will have a diameter of 35 mm. The sectionof this central portion will then have no discontinuity and its lowerbase will be connected also without discontinuity of section with anupper truncated cone shaped part of pin 3. The flat piece 5 will nothave, in this variant, a central recess such as 51 in FIG. 1, but willbe directly fitted on to the central part 2.

In this variant, simpler to construct than that of FIG. 1, the centraltruncated cone shaped part 2, by being engaged at the outset in thesleeve of the peg, will be jammed therein and, from the first impacts ofthe ram, the peg will be splayed out while rising along the centraltruncated cone shaped part 2, which will facilitate introduction of thepost at the end of the operation. No risk of damaging the sleeve of thepeg by upsetting exists.

In FIGS. 2 and 3, it can be seen that the ram comprises a cylindricalsleeve 6 having for example a length of 600 mm, an outer diameter of 80mm (equal to that of the striking surface 42) and an inner diameter of31 mm, so slightly greater than that of the handle 1 on which it slides.

The relatively large height and the relatively small section of the ramprovide better guiding of sliding with longer travel and an impact veryclosely centered on the striking surface.

In the example described, four handles 7,8,9,10 are provided disposeduniformly around the periphery of sleeve 6 and firmly fixed thereto at asingle one of their ends. In fact, it has been discovered that securingthe handle at both ends would cause a rigidity such that the shock waveswould break the joints after a certain operating time. Preferably, thehandle is secured at its lower part by a longitudinal weld 71, whichoffers very high resistance to tearing by the shock wave which takesplace near-by. The top part of the handles is left free, which allowsdissipation of the shock wave; so as to avoid however secondary parasitevibrations and deformations, this top part is curved at a level higherthan that of the upper end of the sleeve and its end comes down andpenetrates with a very small clearance in a channel 72 provided in thebody of the annular sleeve and opening into the outer transverse surfacethereof. A gap 73 is provided between the endmost surface of the handleand the bottom of the channel.

The handle 1 of the body of the tool could be truncated and the upperpart thereof and the ram replaced by the piston of a hydraulic cylinder,or by any other mechanical driving device, the advantages provided bythe construction of the central and lower parts of body 1 beingretained.

Though the tool which has been disclosed is not usable exclusively withthe peg described in prior U.S. patent, it has been more particularlydesigned for adapting thereto.

What is claimed is:
 1. In combination:i--a peg for fixing posts andstakes in the ground, said peg comprising a rigid member including atleast two assembled metal plates which define an elongate central sleeveadapted to receive a base portion of said post or stake and formprojecting fins, said projecting fins having an upper edge surface; andii--a tool for driving said peg into the earth, said tool comprising arigid elongate body having a lower part which has, at least on a portionof the length thereof, a cross-section which substantially matches thecross-section of said central sleeve for insertion of said lower partinto said central sleeve, an upper part and a projecting central partand means, cooperating with said upper part, for imparting axiallydirected blows on said projecting central part, said projecting centralpart comprising: an upper portion of enlarged cross-section and a lowerportion with a reduced cross-section substantially matching thecross-section of said central sleeve; a bell-shaped member capping thesaid upper portion and having a base and an upper surface portion whichis provided with a central passage for the said upper part and forms astriking surface for said means; and a transverse flat member having acentral aperture forming a passage for the said lower portion of theprojecting central part, said flat member having an upper surface whichis assembled with the base of the bell-shaped member and a lowertransverse surface which is adapted for bearing on the upper edgesurface of the projecting fins of the peg and is located at a distancefrom the end of said lower part at least equalling the length of thesleeve of the peg.
 2. The combination, as claimed in claim 1, whereinsaid upper, central and lower parts of the elongate body are formed as asingle member.
 3. The combination, as claimed in claim 1, wherein saidlower part of the elongate body has an endmost portion whosecross-section substantially matches that of the sleeve of the peg, saidendmost portion having a pointed end, and an upper portion of reducedcross-section.
 4. The combination, as claimed in claim 1, wherein thesaid means for imparting axially directed blows to the said strikingsurface comprise a sleeve forming a ram mounted for sliding along saidupper part of the elongate body, at least first and second handles eachhaving an elongate lower end portion which is firmly secured to thesleeve and an upper curved end portion which penetrates freely into alongitudinal channel which opens into the upper endmost surface portionof the sleeve, said channel having a depth greater than the length ofthe handle portion which penetrates therein.
 5. The combination, asclaimed in claim 1, wherein said transverse flat member is provided withstrengthening fins formed integral with the said bell-shaped member andthe lower transverse surface is provided with a plurality of lighteningperipheral notches and with grooves adapted for positioning thebell-shaped member on the fins of the peg.